One third of global population overweight or obese according to new study

More than 2 billion people around the world are either overweight or obese, according to a recent study published in The New England Journal of Medicine.
This figure means that nearly one third of the global population suffer from excess weight, and according to the researchers this excess weight is leading to health problems and a rising number of deaths. The study, entitled “Health Effects of Overweight and Obesity in 195 Countries over 25 Years,” systematically reevaluated the trends in the prevalence of overweight and obesity as well as the patterns of deaths and disability-adjusted life-years related to high body mass index (BMI), according to age and sex, in 195 countries from 1990 through 2015.

China obesity

Research data indicates that in 2015, China had the highest numbers of obese children (15.3 million), and the second highest (behind only the United States) number of obese adults (57.3 million). These high numbers are largely attributable to China’s massive population.

On a per-capita basis, the research data indicates that China ranks lower in terms of levels of obesity among both children and adults, but still rather high. In China in 2015:

Overweight adults (ages >= 20) accounted for around 25.71% of males and 22.78% of females(as compared with 39.84% of males and 29.46% of females in the United States).

Obese adults (ages >= 20) accounted for around 5.02% of males and 5.51% of females(as compared with 30.66% of males and 35.45% of females in the United States).

Overweight children (ages 2-19) accounted for around 12.34% of males and 9.82% of females(as compared with 15.79% of males and 15.82% of females in the United States).

Obese children (ages 2-19) accounted for around 5.91% of males and 4.24% of females(as compared with 12.99% of males and 12.4% of females in the United States).

Moreover, while the levels of obese adults and children in China are still significantly lower than those in the United States, the rate at which levels have risen in China is quite shocking. In China in 1980:

Overweight adults (ages >= 20) accounted for only around 5.23% of males and 9.28% of females(as compared with 25.71% of males and 22.78% of females in 2015).

Obese adults (ages >= 20) accounted for only around 0.33% of males and 0.9% of females(as compared with 5.02% of males and 5.51% of females in 2015).

Overweight children (ages 2-19) accounted for only around 2.54% of males and 2.87% of females(as compared with 12.34% of males and 9.82% of females in 2015).

Obese children (ages 2-19) accounted for only around 0.8% of males and 0.83% of females(as compared with 5.91% of males and 4.24% of females in 2015).

Levels of obesity have also risen in the United States between 1980 and 2015, but not by as much as they have in China during this period. Additional data is available in the study’s Supplemental Appendix.

Body mass index (BMI)

“Obese” and “overweight” are categorized according to BMI, which is calculated as weight in kilograms divided by height in meters squared:

BMI between 19 and 24 is considered normal and healthy.

BMI between 25 and 29 is considered overweight.

BMI over 30 is considered obese.

Sociodemographic index (SDI)

The study also analyzed sociodemographic index (SDI) — a summary measure of lag-distributed income per capita, average educational attainment among persons over the age of 15 years, and total fertility rate — to position countries on the development continuum. We then generated quintiles of SDI to categorize countries as low, low-middle, middle, high-middle, and high development level. China was categorized as middle SDI (while the United States was categorized as high SDI).

Among the leading health risks that were assessed in the Global Burden of Disease 2015 study, high BMI continues to have one of the highest rates of increase. Across levels of development, the prevalence of obesity has increased over recent decades, which indicates that the problem is not simply a function of income or wealth. Changes in the food environment and food systems are probably major drivers. Increased availability, accessibility, and affordability of energy-dense foods, along with intense marketing of such foods, could explain excess energy intake and weight gain among different populations. The reduced opportunities for physical activity that have followed urbanization and other changes in the built environment have also been considered as potential drivers; however, these changes generally preceded the global increase in obesity and are less likely to be major contributors.

Health concerns

Cardiovascular disease was the leading cause of death and disability-adjusted life-years related to high BMI. Other causes of death related to high BMI include chronic kidney disease, cancers, diabetes, and musculoskeletal disorders.